Apparatus for separating solids from liquids



Dec. l1, 1928. Y 1,695,193

' R. F. KRALL APPARATUS FOR SEPARATING SOLIDS FROM LIQUIDS Filed April24', 1926 ff QM/@ Patented Dec. 11, 1928.

UNITED STATES PATEN'T' GFFICE.

REGINALD FRANK KRALL, OF LONDON, ENGLAND, ASSIGNOR T IVOODlIiL-DUCKHAM(1920) LIMITED, 0F LONDON, ENGLAND, A BRITISH COMPANY.

APPARATUS SEPARATING -SOLIDS FROM LIQUIDS.

Application led April 24, 1926, Serial No. 104,460, and in Great BritainAugust 28, 1925.

on to a distributing plate mounted on a verf tical shaft which isco-axial with a substantially conical screen, also mounted larger enddownwards, on the shaft. The shaft being rotated the material is thrownoft the plate against the screen down which it travels, preferably insteps as described in the said specitication,becoming dried during itsprogress. At the bottom of the screen it is thrown against the wall of astationary hopper wherein it collects.

The present invention relates to improvements in apparatus of this kindfor the purpose of facilitating its operation and rendering it moreeilicient.

In the known construction it was found necessary to provide the`necessaryy clearance between the rotating screen and the collectinghopper by means of a tortuous passage in order to avoid entry of thewater spray, which fills the closed casing around the screen, throughthe clearance into the ho per, where it would re-wet the material. Itwas found, however, that, since dust would enter the clearance andbecome caked when the machine was idle, difficulties were encounteredwhen the machine was to be restarted and which required a highexpenditure of power.

An object of the present invention is to overcome the disadvantagesassociated with the known type of apparatus referred to. For thispurpose, theclearance between the lower part of the rotating screen andthe hopper which receives the dried material is formed between a pair ofrings, thin in the radial direction, one of which Vdepends from thescreen and the other of which extends upwardly from the hopper, with thelower edge of the depending ring in close proximity to the upper edge ofthe upstanding ring. The clearance between these two rings may bereduced to such small dimensions that the quantity of caked dustexisting in it when indicated. From the screen the material passes intothe hopper (Z, the upper part of which is alone shown in the drawing.

In the known construction the casing e is closed to the atmosphere; inthe present case the casing has openings f. To act as a water collectingscreen there is a non-perforated hood g depending from the top of thecasing; the water draining from this hood falls into the trough 7i. l

The joint between the bottom ring c of the screen and the ring CZ which.carries the hopper d is shown in Fig. 8. The ring c carries a dependingring c2 and the ring d an upstanding ring Z2 of the Vsame diameter. Theclearance between these rings c2, cl2 may be reduced to such smalldimensions that the quantity of caked dust which may exist in it whenthe machine is to be re-started cannot create any diiiiculty. By settingthe ring o2 at some little distance from the periphery of ring c asindicated, the clearance between rings c2 and Z2 is sheltered from watersplashing.

In the modification shown in Fig. 2 the upper part of the casing o iseliminated, the frame members z' being provided merely for carrying theusual machinery guards for protecting operatives. The shaft 7c carrieson arms Z the conical non-perforatedplate m on the interior surface ofwhich are studs n; to the latter the conical screen c is suitablyattached. Thus the plate which collects the water rotates, with theadvantage that there is less splashing thanvwhen the screen isstationary.

This last-named advantage may facilitate the construction because theclearance between the screen and the collecting hopper d may be as largeas is reasonable. In the case shown on the right hand side of Fig. 2 thelowest ring c of the screen carries a conical ring 0 which extends intothe mouth ot the hopper Z with considerable clearance, the latter beingprotected by a similar conical ring p carried by the casing andextending upwards sutliciently to intercept drops trom the plate m.

The rotary plate fm lends itself to ready washing, and for this purposea water-pipe g is arranged to discharge aga-inst the upper part ot' theinteriorsurtace of the plate. This involves a somewhat heavy dischargeot water and the modification shown on the lett hand side ot Fig. Q ispreferable. Here a battle-ring 9' to detlect the water directly into thetrough 7L, is carried by the trame members fi. A 'joint is constructedat s similar to that shown in Fig. 3.

Having thus fully described the nature ot the said invention and thebest means I know ot carrying the` saine into practical e'fiiect, Iclaim l. A drying apparatus comprising a substantially conical screenhaviiig its axis substantially vertical. and its larger end extendingdownwardly and adapted to be rotated about its axis, means forprojecting particles of material to be dried against the inner surtaceot the screen, means tor feeding material to the said projecting means,a hopper positioned below said screen to receive dried inaterialleavingl the lower end' of the screen, a ring depending from saidscreen, and a ring coaxial with and ofthe saine diameter as saidtiret-named ring and upstanding from the hopper with its upper edge inclose proximity to the lower edge oit the first-named ring andcooperating with the latter to term a clearance between the screen andthe hopper.

2. An apparatus according to claim l comprising an imperi'iorate platesurrounding and supporting the screen.

3. A drying apparatus comprising a substantially conical screen havingits axis substantially vertical and its larger end extending downwardlyand adapted to be rotated about its axis, means for projecting particlesol" material to be dried against the inner surface of said screen, meansfor feeding material to said projecting means, a hopper positioned belowsaid screen and adapted to receive dried material as it leaves the lowerend ot the screen, atroughsurrounding the hopper and a conical ringextending upwardly from the mouth of the hopper into proximity to thelower end of the screen to divert splashes of liquid from the clearancebetween said mouth and the screen into said trough.

' 4. An apparatus according to claim l, comprising a conical platesurrounding and spaced from the screen and means tor discharging waterupon the upper part ot the inner surface of said plate. y

5. An apparatus according to claim l, coinprising a conical platesurrounding and spaced from the screen, a trough below the lower end ot'said plate, means t'or discharging water against the inner surface otsaid plate anda baille to receive the water as it leaves said plate anddirect it into said trough.

6. A drying apparatus comprising a substantially conical screen havingits axis substantially vertical and its larger end extending downwardlyand' adapted to be rotated about its axis, means tor projectingparticles ot material to be dried against the inner surtace ot thescreen, means tor feeding material to the said projecting means, ahopper positioned below said screen to receive dried materialleaving'the lower end ot the screen, a ring depending from said screenand ot slightly less diameter than the external diameter of the lowerend of the screen, and a ring coaxial with and of the saine diameter assaid tirst-named ring and upstanding from the hopper with its upper edgein close proximity to the lower edge ot the tirst-named ring andcooperating with the latter to form a clearance between the screen andthe hopper.

In testimony whereof I have signed my name to this specification.

' REGINALD FRANK KRALL.

